Hydrogenation reactions are fundamental in the fine chemical, pharmaceutical, and petrochemical industries, however heavily relying on H2 gas at high temperatures and pressures, incurring large energy and carbon costs. Photocatalytic transfer hydrogenation, using water as a proton source, offers a greener alternative, but existing photocatalysts often suffer from modest yields, limited selectivity, and narrow substrate scope. Additionally, they often require co-activation, such as Mg-activated water or non-sustainable hydrogen feeds. Here, a photocatalyst is introduced that offers high yields and selectivities across a broad spectrum of organic compounds. The developed photocatalyst is a multivalence palladium superstructure with ultrasmall Pd0 nanoparticles enveloped by isolated Pd2+/Pd4+ atoms within a carbon-nitride matrix. Mechanistic studies reveal that the redox-flexible Pd single atoms, with triethylamine as an electronic modulator, attract photogenerated holes for water oxidation, while Pd0 nanoparticles facilitate hydrogen transfer to the unsaturated bonds of the organic molecules. The cooperative and dynamic behavior of Pd centers during catalysis, involving transitions among Pd+2, Pd+3, and Pd+4 states, is validated using operando electron paramagnetic resonance spectroscopy. This multivalent palladium catalyst represents a conceptual advance in photocatalytic transfer hydrogenation with water as a hydrogen source, holding promise for sustainable hydrogenation processes in the chemical industry.

• Keywords
• carbon nitride, hydride transfer, palladium, photocatalysis, selective hydrogenation,
• Publication type
• Journal Article MeSH

This roadmap reviews the new, highly interdisciplinary research field studying the behavior of condensed matter systems exposed to radiation. The Review highlights several recent advances in the field and provides a roadmap for the development of the field over the next decade. Condensed matter systems exposed to radiation can be inorganic, organic, or biological, finite or infinite, composed of different molecular species or materials, exist in different phases, and operate under different thermodynamic conditions. Many of the key phenomena related to the behavior of irradiated systems are very similar and can be understood based on the same fundamental theoretical principles and computational approaches. The multiscale nature of such phenomena requires the quantitative description of the radiation-induced effects occurring at different spatial and temporal scales, ranging from the atomic to the macroscopic, and the interlinks between such descriptions. The multiscale nature of the effects and the similarity of their manifestation in systems of different origins necessarily bring together different disciplines, such as physics, chemistry, biology, materials science, nanoscience, and biomedical research, demonstrating the numerous interlinks and commonalities between them. This research field is highly relevant to many novel and emerging technologies and medical applications.

• Publication type
• Journal Article MeSH
• Review MeSH